Unknown issue/fault = engine check light ??? no logged fault ??? how do I go about diagnosis/elimnation process

[kuruptkiwi]

HELP/EXPERIENCE NEEDED

 

2005 BA MK2 Falcon XR6T 4sp Auto 

 

hi all, any advice or info will be VERY much appreciated, im certainly no expert but do have good general understanding of automotive/mechinical knowledge to apply any help or helpful diagnosis process anyone may have to offer....ok so....

 

having issue pretty much everytime I cold start,

turning car off then back on usually rectifys or atleast stops the symptoms...

very intermittant when,why,what seems to cause the fault or how long after starting (hot or cold start, )(9/10 times cold it faults) sometimes it isn't till a gear is selceted before faulting. 

 

so when this "Fault" occurs it always illuminates Check engine Light, aswell as throttle imediately pulses up and down but no longer responds to any apllied or not applied throttle pressure and seems/feels alot like a poteintial limp mode reaction, (if in gear car will lurch as it pulses, forward or reverse)

 

more often than not simply turning igntion to off then restarting seems to reset or clear the symtoms including no engine light at all after on/off.......but very fustrating to have to go through this process once or more times everytime I use the car (gets a lil imbarrassing tbh)........so ive checked car with plug in obd tool's to see any logged faults aswell as tried clearing all faults, tried unplugging battery and different reset methods and this issue still remains or presists, yet FAULT LOG does not record/log or even indicate the code or fault relating to the origin of the issue/fault/malfunction.

 

if the above ignition off/on process is or is not needed within 30 seconds of start up and onwards this fault has never happned there after or while driving, atleast not untill the next time attemting to start. also have not noticed any relating performance issues, noises or related faults, codes or any other check lights to appear at all

 

im lost on how to go about diagnosing the origin of this without poteinally wasting lots of time and money on everything but what is required to fix  or solve this 

 

thanks heaps for taking time to read and thanks HEAPS for any help or direction you have to offer

Edited 04/05/23 03:29 AM by kuruptkiwi

[TurboBurbo]

Engine light but no codes tends to be a scanner issue. I've found examples online of the go-to TorquePro app not picking up misfire errors in a Hyundai, but Carista OBDII did. So I'd try some different apps.

[Puffwagon]

I must have missed this thread.

 

Based on the post it seems like it has an issue with the throttle body. I'd start by giving it a thorough clean, they are very sensitive to being dirty in regard to idle and start up.